Alexis yernaz



(No Model.)

A. VERNAZ. CHECKING DEVICE FOR SPROGKET WHEELS 0F MUSICAL INSTRUMENTS.

No. 558,442. Patented Apr. 14, 1896.

AN DREW BJSRAHAM. PHOTO-LITHDWASHINGTOK D C UNITED STATES PATENT OFFICE,

ALEXIS VERNAZ, or srn. OROIX, SWITZERLAND, AssieNoR TO MERMOD FRnREs, or SAME PLACE.

CHECKING DEVICE FOR SPROCKET-WHEELS OF MUSICAL INSTRUMENTS.

SPECIFICATION forming part of Letters Patent No. 558,442, dated April 14, 1896.

Application filed anuary 6, 1 8 9 6.

To aZZ whom it may concern.-

Be it known that I, ALEXIS VERNAZ, a citi zen of the Republic of France, and a resident of Ste. OroiX, Canton of Vaud, Switzerland, have invented a new and useful Checking Device for the Sprocket -Wheels of Musical Instruments, of which the follewin g is an exact specification.

This invention refers to musical instruments of that sort in which tongues or reeds are operated from a perforated note plate or disk by the mediation of sprocket-wheels, the teeth of which take into the perforations of said note-plate and are eompulsorily moved by the same. There is in said instruments the drawback that a certain number of teeth (those which at any given moment are situated close at the note-plate, or, more precisely, close at the solid or non-perforated portions of said plate) constantly glide upon the said plate. There is thus produced a scratching noise, making the tones unclear, and said teeth, as well as the note-plate, are very soon worn away.

The purpose of my invention is to do away with the drawbacks just mentioned, and I attain that object by checking each sprocketwheel after the tooth last acted on by the noteplate has left the respective perforation of the same, or before the tooth to be acted on next has touched said plate, respectively. Said checking is effected by levers arranged one close to each sprocket-wheel, and caused, by means of springs, to bear very slightly upon the note-plate. Said levers, or, more precisely, the points or noses of the same, enter the perforations; but said points or noses of the checking-levers enter the perforations of the note-plate just as do the teeth of the sprocket-wheels; but said points or noses of the checking-levers enter the perforations of the note-plate before the teeth of the sprocketwheels and free thereby the latter.

In order to make my invention more clear, I refer to the accompanying drawings, in which similar letters refer to similar parts throughout the different views, and in which Figure 1 shows a sprocket-wheel, the lever belonging to the same, and a portion of the note-plate. Fig. 2 shows the same parts in another position. Fig. 3 shows again the Serial No. 574,542. (No model.)

same parts in a third position, and Fig. 4 is a plan of some of said sprocket-wheels and of some of said levers.

There are in a musical instrument of the sort in question as many sprocket-wheels as there are concentric circles of perforations in the note-plate. In the form of construction shown all sprocket-wheels are arranged upon a common shaft f, which, while the instrument is at work, rotates in the direction indicated by the arrow in Figs. 1, 2, and 3. Said shaft f is generally the one transmitting the motion of the wheel-work (not shown) upon the circular note plate or disk; but I wish it to be understood that I need not use the said shaft for that purpose, as my novel arrangement may be employed with circular note-plates as well as with band-like ones. The main purpose, or, may be, the single purpose, of the rotating shaft is to carry the teeth of the sprocket-wheels into the perforations of the note-disk, as only then the latter is able to act upon said wheels. In order to obtain a sufficient friction between the shaft and the said sprocket-wheels, I furnish each of the latter with a small spring g, situated in a suitable recess of the respective wheel.

Each of the sprocket-wheels is, as has already been stated in the preamble, combined with a lever c, the nose-like end 0 of which is caused to bear upon the note-plate I) under the influence of a spring (Z. Each of said levers c is provided with a small projection c, that serves as a check for the sprocket-wheel. The position of said projection with regard to the teeth of the sprocket-wheel is such a one that it acts as a check then only when the two teeth preceding the tooth next to be checked lie directly below the note-plate, as is clearly represented in Fig. 1. Said tWo teeth, when in' this position, do not touch the note-plate, and there cannot possibly be any scratching whatever.

It is to be seen from Fig. 1 that the nose 0 of the lever c is'situated between the two teeth a a of the sprocket-wheel. The distance between said nose and that one of said teeth which is situated next to the fulcrum of the lever c is considerably shorter than the length of one of the shortest perforations of the noteplate I). If, therefore, one of those perforations comes to pass over the said nose 0, the latter will, under the action of the spring d, instantly enter the said perforation, and the projection e of the lever 0 will thereby be raised as much as to release the sprocketwheel a. The latter is now free to rotate, together with the shaft f, and one of its teeth will enter the perforation containing the nose of the leverc. (Compare Fig. 2.) The velocity of rotation of the note-plate I) is greater than that of the shaft f, and said note-plate Will therefore catch the tooth just mentioned and will move the respective sprocket-wheel compulsorily, so as to operate the tongue or reed belonging to that sprocket-wheel. The lever c, with its projection c, has during this time regained its former position, Fig. 3, and will thus check the rotation of the sprocket-wheel as soon as the next tooth of the latter pushes upon the said projection 6. It will be understood that the rotation of the sprocket-Wheel proceeds also when the compulsory action of the note-plate has ceased, and the tooth having been acted on by the note-plate is thus perfectly prevented from gliding upon the same, as is also the tooth next to be acted 011.

Having thus fully described the nature of this invention, what I desire to secure by Letters Patent of the United States is- 1. In a musical instrument having tongues, sprocket-wheels for operating said tongues, and perforated note-plates for operating said sprocket-wheels, the combination with a shaft carrying the said sprocket-Wheels, and adapted to rotate them independently of the action of said note-plates, of means adapted to check either of the sprocket-wheels, and to be operated by the said n etc-plates, for the purpose as described.

2. In a musical instrument having tongues, sprocket-wheels for operating said tongues, and perforated note-plates for operating said sprocket-Wheels, the combination with a shaft carrying the said sprocket-Wheels, and adapted to rotate them independently of the action of said note-plates, of levers adapted to check either of the sprocket-Wheels, and arranged so as to be adapted to be operated by the said note-plates, for the purpose as described.

3. In a musical instrument having tongues, sprocket-wheels for operating said tongues, and perforated note-plates for operating said sprocket-Wheels, the combination with a shaft carrying the said sprocket-wheels, and adapted to rotate them independently of the action of said note-plates, of levers adapted to check either of the sprocket-Wheels, and arranged so as to be adapted to be operated by the said note-plates, said levers having projections adapted to perform said checking, and having other projections adapted to enter the perforations of the note-plates, substantially as de scribed.

at. In a musical instrument having tongues, sprocket-Wheels for operating said. tongues, and perforated note plates for operating said sprocket-wheels, the combination with a shaft carrying the said sprocket-Wheels, and adapted to rotate them independently of the action of said note-plates, of means adapted to check either of the sprocket-wheels, and to be operated by the said note-plates; each of said sprocket-wheels having a spring inserted between said wheel and said shaft, said spring being situated within a recess of the said Wheel, for the purpose as described.

111 testimony whereof I have signed this specification in the presence of two subscribin g witnesses.

ALEXIS VERNAZ.

\Vitnesses BENJ. II. RIDGELY, E. F. BARRY. 

